package com.binarytree;

public class Solution31 {
    public TreeNode trimBST(TreeNode root, int low, int high) {
       if (root == null) return null;

       if (root.val < low) {
           return trimBST(root.right,low,high);
       } else if (root.val > high) {
           return trimBST(root.left,low,high);
       }
       root.left = trimBST(root.left,low,high);
       root.right = trimBST(root.right,low,high);
       return root;
    }


}
